Build redirect paths for all known Steam Paths

This will ensure that if Steam is located on another disk, we're still
able to locate the LibraryFolders stanza in `libraryfolders.vdf` and
add all applicable rules given the realpath()'d resolved paths.

Signed-off-by: Ikey Doherty <ikey@solus-project.com>

src/common/files.c

@@ -11,6 +11,7 @@
 
 #define _GNU_SOURCE
 
+#include <ctype.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -20,7 +21,12 @@
 
 #include "common.h"
 #include "files.h"
+#include "log.h"
+#include "nica/array.h"
 #include "nica/util.h"
+#include "vdf.h"
+
+DEF_AUTOFREE(VdfFile, vdf_file_close)
 
 bool lsi_file_exists(const char *path)
 {
@@ -98,6 +104,95 @@ char *lsi_get_process_name(void)
         return strdup(basep);
 }
 
+/**
+ * Quickly determine if a string is numeric..
+ */
+static inline bool lsi_is_string_numeric(char *p)
+{
+        char *s;
+
+        for (s = p; *s; s++) {
+                if (!isdigit(*s)) {
+                        return false;
+                }
+        }
+
+        /* Didn't wind, empty string */
+        if (s == p) {
+                return false;
+        }
+        return true;
+}
+
+char **lsi_get_steam_paths(void)
+{
+        autofree(char) *steam_root = NULL;
+        autofree(char) *lib_conf = NULL;
+        autofree(VdfFile) *vdf = NULL;
+        VdfNode *root = NULL;
+        VdfNode *node = NULL;
+        NcArray *array = NULL;
+
+        steam_root = lsi_get_steam_dir();
+        if (!steam_root) {
+                return NULL;
+        }
+
+        array = nc_array_new();
+        if (!nc_array_add(array, strdup(steam_root))) {
+                goto bail;
+        }
+
+        if (asprintf(&lib_conf, "%s/steamapps/libraryfolders.vdf", steam_root) < 0) {
+                return NULL;
+        }
+
+        vdf = vdf_file_open(lib_conf);
+        if (!vdf) {
+                goto fallback;
+        }
+
+        if (!vdf_file_parse(vdf)) {
+                goto fallback;
+        }
+
+        /* Look up LibraryFolders under root */
+        root = vdf_file_get_root(vdf);
+        node = vdf_node_get(root, "LibraryFolders", NULL);
+        if (!node) {
+                goto fallback;
+        }
+
+        /* Walk all nodes immediately within LibraryFolders and ignore sections */
+        for (VdfNode *n = node->child; n; n = n->sibling) {
+                if (!n->value) {
+                        continue;
+                }
+                if (lsi_is_string_numeric(n->key)) {
+                        if (!nc_array_add(array, strdup(n->value))) {
+                                goto bail;
+                        }
+                        lsi_log_debug("vdf: discovered LibraryFolders: %s", n->value);
+                }
+        }
+
+fallback:
+        /* Trick nica into storing empty value to so we can terminate the array */
+        if (!nc_array_add(array, (void *)(long)1)) {
+                goto bail;
+        }
+
+        /* Steal the blob straight out of the array */
+        char **data = (char **)array->data;
+        data[array->len - 1] = NULL;
+        free(array);
+        return data;
+
+bail:
+        nc_array_free(&array, free);
+        return NULL;
+}
+
 /*
  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  *

src/common/files.h

@@ -31,6 +31,11 @@ char *lsi_get_user_config_dir(void);
  */
 char *lsi_get_steam_dir(void);
 
+/**
+ * Grab all the valid steam installation directories
+ */
+char **lsi_get_steam_paths(void);
+
 /**
  * Quick helper to determine if the path exists
  */

src/redirect/main.c

@@ -134,13 +134,12 @@ failed:
 /**
  * Testing: Create profile for ARK: Survival Evolved
  */
-static LsiRedirectProfile *lsi_redirect_profile_new_ark(void)
+static LsiRedirectProfile *lsi_redirect_profile_new_ark(char **steam_paths)
 {
         LsiRedirectProfile *p = NULL;
         LsiRedirect *redirect = NULL;
 
 #define ARK_BASE "steamapps/common/ARK/ShooterGame/Content"
-        autofree(char) *steam_dir = NULL;
         autofree(char) *mic_source = NULL;
         autofree(char) *mic_target = NULL;
         static const char *def_mic_source =
@@ -155,19 +154,28 @@ static LsiRedirectProfile *lsi_redirect_profile_new_ark(void)
                 return NULL;
         }
 
-        steam_dir = lsi_get_steam_dir();
-        if (asprintf(&mic_source, "%s/%s", steam_dir, def_mic_source) < 0) {
-                goto failed;
-        }
-        if (asprintf(&mic_target, "%s/%s", steam_dir, def_mic_target) < 0) {
-                goto failed;
+        /* For each steam path, try to create a rule for it */
+        while (*steam_paths) {
+                char *steam_dir = *steam_paths;
+
+                if (asprintf(&mic_source, "%s/%s", steam_dir, def_mic_source) < 0) {
+                        goto failed;
+                }
+                if (asprintf(&mic_target, "%s/%s", steam_dir, def_mic_target) < 0) {
+                        goto failed;
+                }
+
+                /* Don't add a redirect if the paths don't exist. */
+                redirect = lsi_redirect_new_path_replacement(mic_source, mic_target);
+                if (!redirect) {
+                        goto next;
+                }
+
+                lsi_redirect_profile_insert_rule(p, redirect);
+        next:
+                ++steam_paths;
         }
 
-        redirect = lsi_redirect_new_path_replacement(mic_source, mic_target);
-        if (!redirect) {
-                goto failed;
-        }
-        lsi_redirect_profile_insert_rule(p, redirect);
         return p;
 
 failed:
@@ -189,6 +197,7 @@ __attribute__((constructor)) static void lsi_redirect_init(void)
         /* Ensure we're open. */
         lsi_redirect_init_tables();
         autofree(char) *process_name = NULL;
+        char **paths = NULL;
 
         process_name = lsi_get_process_name();
 
@@ -197,19 +206,33 @@ __attribute__((constructor)) static void lsi_redirect_init(void)
                 return;
         }
 
+        /* Grab the stam installation directories */
+        paths = lsi_get_steam_paths();
+
         /* Temporary hack, we'll make this more generic later */
-        if (strcmp(process_name, "ShooterGame") == 0) {
+        if (strcmp(process_name, "ShooterGame") != 0) {
                 lsi_log_set_id("ShooterGame");
-                lsi_profile = lsi_redirect_profile_new_ark();
+                lsi_profile = lsi_redirect_profile_new_ark(paths);
         }
 
         if (!lsi_profile) {
-                return;
+                goto clean_array;
         }
 
         lsi_override = true;
-
         lsi_log_debug("Enable lsi_redirect for '%s'", lsi_profile->name);
+
+clean_array:
+
+        /* Free them again */
+        if (paths) {
+                char **orig = paths;
+                while (*paths) {
+                        free(*paths);
+                        ++paths;
+                }
+                free(orig);
+        }
 }
 
 _nica_public_ int open(const char *p, int flags, ...)